Internal-combustion engine



J. S. OLIVER INTERNAL COMBUSTION ENGINE Feb. 5, 1929.

Filed April 1926 Patented Feb. 5, 1929.

UNITED STATES PATENT OFFICE.

JOHN SCOTT OLIVER, OF LONDON, ENGLAND.

INTERNAL-COMBUSTION ENGINE.

Application filed April 8, 1926, Serial No. 100,514, and in Great Britain January 14, 1926.

This invention relates to internal combustion engines and the like and more particular 1y to valves and Valve mechanism therefor, and the object of the invention is to provide an improved form of sleeve valve mechanism having a simple rotary movement, which will enable a more rapid opening and closing of the inlet and exhaust ports to be obtained than has hitherto been possible with rotary sleeve valves.

According to the invention, an internal combustion engine is provided with a rotary sleeve valve provided with two ports or sets of ports each adapted to register alternately with inlet and exhaust ports in the cylinder, the first port or set of ports extending from a point at or near the head of the cylinder to a point intermediate the stroke of the piston whilst the second set of ports extend from a point intermediate the stroke of the piston to a point at or near the bottom of the stroke of the piston.

In order that the invention may be readily understood, reference will now be made to the accompanying drawings in which Figure 1 is a section through the cylinder and crank case of any internal combustion engine provided with sleeve valve according to the invention.

Figure 2 is a section on the line 22 of Figure 1, and

Figure 3 is a section on the line 33 of Figure 1.

As shown in the drawings, the piston 1 works in a rotary sleeve 2 disposed between the piston and the walls of the cylinder and provided with two ports 3 and 4 of which the port 3 registers alternately with an inlet port 5 and an exhaust port 6 in the cylinder whilst the port 4 registers alternately with an inlet port 7 and an exhaust port 8 in the cylinder. The sleeve 2 is formed with or secured to a worm wheel 9 meshing with a worm 10 driven from the crank shaft through suitable gearing such that the sleeve 2 makes one revolution during two revolutions of the crank shaft. ()ther suitable gearing may, however be substituted for the worm and worm wheel.

In the construction shown in the drawings the inlet port 5 is opened by the port 3 at top of crank of the induction stroke and closed by the port 3 at after bottom of crank of the induction stroke whilst the exhaust port 6 is opened by the port 3 at 40 before bottom of crank of the firing stroke and closed by the port 3 at top of crank of the exhaust stroke.

The ports 3, 5 and 6 each subtend an angle of and the ports 5 and 6 are set apart at an angle of 110.

The ports 3, 5 and 6 extend from a point near the head of the cylinder to a point a which corresponds to the position of the top of the piston at 40 from bottom of crank and the ports 4, 7 and 8 extend from the point a to a point 6 which corresponds to the position of the top of the piston at bottom oi crank. The port 4 is therefore uncovered at 40 beforebottom of crank and covered at 40 after bottom of crank by the movement of the piston and in order toprevent opening of either of the ports 7 and 8 at the wrong times it is only necessary to provide for closing of the inlet port 7v by the sleeve 2 during the period between 40 before bottom of crank and 40 after bottom of crank of the firing stroke and for closing of the exhaust port 8 by the sleeve 2 between 40 before bottom of crank and 40 after bottom of; crank of the induction stroke. The ports 4, 7 and 8 may therefore subtend greater angles than the ports 3, 5 and 6 and the angles subtended may be as great as 90 as in the example shown in the drawings. As shown in the drawings, the port 4 is diametrically opposed to the port 3 whilst the inlet port 7 is in line with the exhaust port 6, but these ports may have any other angular positions so long as the ports 7 and 8 are correctly positioned in relation to the port 4.

Owing to the large opening of the ports 3 and 4 in the sleeve 2, these ports are preferably divided into sections so as to form thin vertical and transverse divisions 11 to avoid any risk of the piston rings amming therein.

In operation the induction port 5 begins to be opened at top of crank of the induction stroke by the port 3 which is progressively uncovered by the piston during the induction stroke from the top of crank to 40 before bottom of crank. At this point the piston begins to uncover the port 4, which has already begun to move across the inlet port 7 and the latter is therefore rapidly opened and closed by the movement of the piston during the period between 40 before bottom of crank and 40 after bottom of crank. At this point the sleeve closes the inlet port 5 and the inlet ports 5 and 7 are. thus simultaneously closed at 40 after bottom of crank.

At 40 before bottom of crank of the firing stroke, the exhaust port (3 is opened by the port 3 and at the same time the port 4, which has already begun to move across the exhaust port 8, is uncovered by the piston, which thus rapidly opens the port 8. At 40 after bottom of crank the exhaust port 8 is closed again by the movement of the piston, but the exhaustport 6 remains open until top of crank ot the exhaust stroke. At this point the sleeve closes the exhaust port 6 and begins to open the inlet port 5 to enable the piston to draw in a new charge.

In the arrangement described with reference to the drawings, the inlet port opens at top of crank and closes stO late whilst the exhaustport opens l0 early and closes at top of crank. It is to be understood however that the invention is not limited to this timing but may be adapted to open and close the inlet and exhaust ports at other times by changing the angular proportions of the ports and by altering the position of the point a.

In order to enable the port t to be completely covered by the piston at top of crank, the piston shown in the drawings is made rather longer than usual. It is within the scope of the invention however to use a shorter piston such that the port l will be partly uncovered by the skirt of the piston at top of crank but it this is done it will be necessary to make the angle of opening of the ports i, 7 and 8 less than 90 so that the ports 7 and 8 will be closed by the sleeve when the port a: is uncovered by the skirt or the piston. For example, if the skirt of the piston begins to uncover the port a at 60 before top of crank, the port a must open the port 7 or 8 not earlier than 60 after top of crank and must close the port 7 or 8 not later than 60 before top of crank so that the total time during which the port 7 or 8 is uncovered by the port 4- mnst not exceed 240 of rotation of the crank, or 120 of rotation of the sleeve.

An internal combustion engine having a piston and a cylinder, a rotary sleeve valve, two sets of inlet and exhaust ports in thecylin der ports in said sleeve valve for registering alternatelywith the inlet and exhaust ports of each set, the firstsetof ports extending from apoint at or near the head of the cylinder to a point intermediate the stroke of the piston andbeing arranged to be opened and closed at the correct times by the move ment of the sleeve alone whilst the second set of ports subtend a wider angle than said first set of ports and extendi'rom a point intermediate the stroke of the piston to a point at or near the bottom of the stroke of the piston and are arranged to be opened and closed at the correct times by the movement of the piston in conjunction Withthe move ment of the sleeve.

In witness whereof I affix my signature.

JOHN SCOTT OLIVER. 

